CE 413 Highway and Traffic Engineering Lecture 1

CE 413

Highway and Traffic Engineering

Lecture 1

Introduction to Transportation Engineering

Engr. Amjad Khan

MS Transportation Engineering (NUST)

Transportation System A transportation system is an infrastructure that

serves to move people and goods efficiently. The transportation system consists of fixed facilities, flow entities, and a control component.

Efficient = safe, rapid, comfortable, convenient, economical, environmentally compatible.

Major transportation subsystems Land transportation: Highway, Rail

Air transportation: Airports

Water transportation: Inland, Coastal, Ocean

JOURNEY SINCE INDEPENDENCE

Description Unit 1947 2014-15

Total Roads Km 50,367 261,595

Motorways Km Nil 650

National

Highways

Km Nil 11,321

Density of

Roads

Km/Km² 0.06 0.32

Vehicles on

Roads

No 21,209 15,168,100

4

RAIL

ROAD RAIL

95% 90%

0% 2%5%8%

90

100

80

70

60

% 50

40

30

20

10

0

Fre

igh

tT

raff

ic

Pass

enger

Tra

ffic

ROAD AIR

RELIANCE ON ROAD NETWORKRELIANCE ON ROAD NETWORK

5

1.62 1.70

1.62

1.04 1.00

0.65 0.68

0.20 0.32 0.230.17 0.15

0.08

1.00

1.50

2.00

3.07

3.50

3.00

2.50

Jap

an

Fra

nc

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Hu

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ary UK

Italy

Ind

ia

US

A

Sp

ain

Ma

lays

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Pa

kis

tan

Bra

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Ind

on

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Ch

ina

Arg

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0.50

Road Density

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Ro

ad

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Countries

INTERNATIONAL ROAD DENSITY COMPARISONINTERNATIONAL ROAD DENSITY COMPARISON

Highway Transportation System Fixed facilities: are the physical components of the system

that are fixed in space and constitutes the network of Links and Nodes. The development of fixed facilities need capital investment.

The Links could be roadway segment and railway track.

The Nodes could be Intersections, Interchanges, Transit terminals, Harbors and Airports.

Flow entities: passenger cars, buses, trucks, pedestrians, etc.

Transportation Engineering

The application of technology and scientific principles to the planning, functional design, operation, and management of roads, streets and highways, their networks, terminals, abutting lands, and relationships with other modes of transportation.

Areas of highway transportation engineering:

Planning of streets and highways

Geometric design of road facilities

Traffic operations and control

Traffic safety

Maintenance of road facilities and controls

Planning•Data Analysis

•Forecasting

•Evaluation

Operations & Management•Traffic

•Maintenance

•Intelligent Transportation

•Safety

•Control

Construction •Surface Preparation

•Grading

•Pavement

•Bridges

Design•Geometrics

•Pavement

•Drainage

•Structural

Experience•Field

•Analysis

•Projects

Research & Development

Transportation Engineering

Road Function Classification

Functional classification is the process by which streets and highways are grouped into classes, or systems, according to the character of service they are intended to provide.

Within the classification of urban and rural, highways are categorized into the following groups:

Arterials

Collectors

Locals

Hierarchical

Structure of

Road Networks

Arterial Roads: The main and primary function of arterial streets is the traffic movement. The arterial collects its traffic from the collector roads. They connect Nation’s principal urbanized areas, cities, and industrial centers. Land access is limited. Posted speed limits on arterials usually range between 50 and 70 mi/h.

Collector Roads: are major and minor roads that connect local roads and streets with arterials. They provide land access. The posted speed limit on collectors is usually between 35 and 55 mi/h.

Local Roads: Provide primary access to residential areas, businesses, farms, and other local areas. Local roads, with posted speed limits usually between 20 and 45 mi/h, are the majority of roads in the U.S.


Mobility

Ability to travel to many different destinations

Provided by Freeways, Motorways…..

Accessibility

Ability to gain access to a particular site or area

Provided by Local Streets

Mobility and Accessibility

In Pakistan the road network comprises of Motorways,National Highways, Provincial and District Roads.

Motorways and national highways form the backbone of highway system, providing inter-provincial linkages along major corridors, and the provincial roads act as feeder roads to the national routes.

The motorways and national highways are managed by National Highway Authority, whereas provincial roads are managed by the respective provinces through their own systems.(e.g. KPHA for kpk)


Difference between Highway and Motorway

Highway Motorway

More traffic

Intersections

Traffic signals/lights

Zebra crossing

Boundary is not provided

May or may not have

control access

Low Speed (70 km/h)

Less traffic

No intersections

No traffic signals/lights

No zebra crossing

boundary is provided

(usually steel wire)

Control access

High speed ( 120 km/h)

HIGHWAY

The National Highways of Pakistan consists of all public highways maintained by National Highways Authority under the Ministry of Transport.

Length…….. 12,000 km

Pakistan’s National highways include the Famous Grand Trunk Road, Indus highway, Karakoram highway and Makran coastal highway

All national highways in Pakistan are pre-fixed with the letter 'N' (for "National") followed by the unique numerical designation of the specific highway (with a hyphen in the middle)

Map of National Highways

Introduction to Motorways

The motorways of Pakistan are a network of multiple-lane, high-speed, controlled-access highways in Pakistan, which are owned, maintained and operated federally by Pakistan's National Highway Authority.

All Motorways in Pakistan are pre-fixed with the letter ‘M' followed by the unique numerical designation of the specific motorway. “E.g. M-5”

Pakistan's Motorways are part of Pakistan's National Trade Corridor Project.

Motorways can be also used by fighter jets for landing and take off.

It is the most secured route in the country.

Challenges for a Traffic Engineer

Challenges for a Traffic Engineer Urban congestion has been a major issue for many years. Given the transportation demand cycle, it is not always

possible to solve congestion problems through expansion of capacity.

Traffic engineers therefore are involved in the development of programs and strategies to mange demand in both time and space and to discourage growth where necessary.

Growth management is a major current issue. Where development will cause substantial deterioration in the quality of traffic service, either such development will be disallowed or the developer will be responsible for general highway and traffic improvements that mitigate these negative impacts.

Trade-off between the desire to reduce congestion and the desire to encourage development as a means of increasing the tax base.

Elements of Traffic Engineering

Elements of Traffic Engineering Traffic Studies

Facility Design

Traffic Operations/ Traffic Control

Performance Evaluation/ Capacity Analyses

Traffic Management System

Intelligent Transportation System (ITS)


Traffic Studies Involve measuring and quantifying various aspect of

highway traffic

Studies focus on data collection and analysis that is usedto characterize traffic, including (but not limited to) trafficvolumes and demands, speed and travel time, delay,accidents, origins and destinations, etc.


Facility design Involves traffic engineers in the functional (Arterial,

Collector and Local) and geometric design of highways and other traffic facilities.

Traffic engineers are not involved in the structural design of highway facilities but should have adequate understanding for structural characteristics of their facilities.


Traffic Operations/ Traffic Control Central function of traffic engineers and involves the

establishment of traffic regulations and their communication to the driver through the use of traffic control devices, such as signs, markings, and signals.

Involves the measures that influence overall operation of traffic facilities, such as one-way street system and surveillance and network control systems.


Performance Evaluation/ Capacity AnalysesIs a mean by which traffic engineers can rate the operating

characteristics of individual sections of facilities.Such evaluation relies on measures of performance quality

and is often stated in terms of “levels of service” Levels of service are letter grades, from A to F, describing

how well a facility is operating using specified performance criteria.

As part of performance evaluation, the capacity of highway facilities must be determined.


Performance Evaluation/ Capacity AnalysesThe six defined levels of service, A-F, describe operations

from best to worst for each type of facility


Traffic Management Systems (TMS) Involves virtually all aspects of traffic engineering in a

focus on optimizing system capacity and operationsSpecific aspects of TMS include high-occupancy vehicle

priority systems, car-pooling programs, pricing strategies to manage demand, and similar functions.


Integration of intelligent transportation system technologies (ITS):

It refers to the application of modern telecommunication technology to the operation and control of transportation system.

Such systems include (but not limited to) automated toll-collection systems, vehicle-tracking systems, in vehicle GPS and mapping systems, automated enforcement of traffic lights and speed laws, Variable Message Signs, Ramp Metering, etc.


Intelligent transportation system technologies

DEFINITIONS

Traffic Volume: Number of vehicles passing aspecified point in a unit time

Traffic Speed: Rate of movement of vehicles thatcan pass a road section. kmph, mph

Traffic Density: Number of vehicles in a particularsection in given unit time. Vehicles/km, vehicles/mile(vehicles/ unit distance)

OR

Number of vehicles per unit length of road.

Rate of Flow: The rate at which vehicles pass a pointduring a specified time period less than one hour,expressed as equivalent hourly rate.

Free flow: A flow of traffic unaffected by upstream ordownstream condition.

Congested flow: A traffic flow condition caused by adownstream bottleneck.

Over Saturation: A traffic condition in which thearrival flow rate exceeds capacity.

DEFINITIONS

CE 413 Highway and Traffic Engineering Lecture 1

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